The present invention refers to a linear actuator, and more in particular to an electro-mechanical linear actuator basically comprising a body, an output member slidably received in the body along an axial direction, an electric motor (or gear motor) and a motion conversion mechanism for converting the rotary motion produced by the electric motor into a translational motion of the output member along the aforesaid axial direction, wherein the motion conversion mechanism includes a driving pulley set into rotation by the electric motor and a cable, or similar elongated mechanical transmission member, which is wound onto the driving pulley and is fastened at its two opposite ends to the output member to draw this latter in either way along the aforesaid axial direction as a result of the rotation of the driving pulley in either direction of rotation.
A linear actuator of the above-identified type is known from European patent application EP1944527. According to this known solution, the two cable lengths leave the driving pulley in a substantially transverse direction relative to the axial direction (direction of the sliding movement of the output member) and are deviated by respective guide pulleys so as to run parallel to the aforesaid axial direction in the same way. One of the two cable lengths is wound onto a third guide pulley, which is located at the axially opposite side of the output member to the driving pulley, to be fastened to the output member itself near the fastening point of the other cable length. The presence of the third guide pulley prevents the output member from being made as a rod which is slidably received in a cylindrical cavity and which partially projects from that cavity. A possible rod should be fastened, on the other hand, to the output member so as to extend alongside the two cable lengths which run among the three guide pulleys and not to be therefore hindered by the third guide pulley. In this way, however, problems of guiding of the rod might arise, since the traction forces alternatively applied by the two cable lengths would not be aligned with the sliding direction of the rod.